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Abstract

This work contains a study of the ion exchange characteristics of the first row transition metal ions Cu²⁺(aq), Co²⁺(aq), Ni²⁺(aq), Mn²⁺(aq) and also Zn²⁺(aq) in ammonium exchanged forms of the synthetic zeolites X and Y. Also reported are investigations into the exchange of Ag⁺(aq) and the amminated species [Ag(NH₃)₂]⁺, [Pt(NH₃)₄]²⁺ and [Pd(NH₃)₄]²⁺ in Na-X, Na-Y and Na-MOR, and [Cu(NH₃)₄]²⁺ in ammonium X and Y only.

Observed effects included sigmoidal isotherms for the exchange of aquated divalent transition metal ions, but no apparent sigmoidal character to the isotherms for exchange involving amminated species. Hydrolysis and possible precipitation was observed with first row transition metal exchange in X (and to a lesser extent Y), and an irreversibility in these isotherms due to either a ternary component in the exchange or exchange into sites not accessible to the ammonium ion at 25°C.

The validity and experimental variation of the analytical techniques used was assessed and consequently the effect of experimental error upon the derived thermodynamic parameters was investigated.

Measured standard free energies and the observed selectivity trends for the systems under investigation have been rationalised using a simple dielectric theory and, in the case of silver(I) exchange, by a modified application of the dielectric theory.

Publication Type:	Thesis (Doctoral)
Subjects:	Q Science Q Science > QD Chemistry T Technology > TP Chemical technology
Departments:	School of Science & Technology > School of Science & Technology Doctoral Theses Doctoral Theses

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